Interpretive Summary: New methods and approaches are needed to control insect pests without the use of pesticides that are hazardous to people and the environment. Scientists at the USDA-ARS Yakima Agricultural Research Laboratory are researching attraction responses of insects as part of a program to develop lures, traps and baits for monitoring and controlling pests on vegetable forage and vegetable crops, including potato. The female-produced pheromone of the adult was characterized, and a sex attractant was developed based on the pheromone chemistry. This attractant provides a much-improved lure for trapping western yellow-striped armyworm to monitor its presence and abundance in agricultural crops. Monitoring information is used in making pest management decisions by farmers and agricultural consultants.

Technical Abstract:
Chemical analysis of solvent extracts of abdominal glands of female western yellowstriped armyworm moths, Spodoptera praefica (Grote), indicated the presence of (Z)7-dodecenol,(Z)7-dodecenyl acetate, (Z)-9-tetradecenyl acetate and (Z)-11-hexadecenyl acetate. In field tests, traps baited with the 3-component blend comprised of (Z)-7-dodecenyl acetate, (Z)-9-tetradecenyl acetate and (Z)-11 hexadecenyl acetate captured numbers of male S. praefica, indicating sexual attraction. Addition of (Z)-7 dodecenol to that blend did not significantly affect lure attractiveness to males. Omission of (Z) -9- tetradecenyl acetate from the 3-component blend significantly reduced lure attractiveness to males, while omission of (Z)-7 dodecenyl acetate eliminated the capture of males in traps. Omission of (Z)-11 hexadecenyl acetate from the 3-component blend did not affect number of males captured. The 4-component blend that included (Z)-7-dodecenyl alcohol attracted more Autographa california (Speyer) moths but fewer moths of several other species that were attracted to the partial blends. The combination of (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate comprises an attractive sex pheromone of female S.praefica and provides an improved attractant for use in trapping males.